Electrical device



Jan. 18, 1927. 1,614,506

' c. c. VAN vooRHls ELECTRICAL DEVICE Filed Feb. 16 1922 INVENTOR CLETUS C. VAN VOORH/S ATTORNEY Patented Jan. 18, 1927.

CLETUS CLINTON VAN VOORHIS,

OF EAST ORANGE, NEW JERSEY, ASSIGNOB TO WESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA;

ELECTRICAL DEVICE.

Application filed February 16, 1922. Serial No. 536,942.

This invention relates and more particularly to rare gas and which are gas or glow lamps.

Gas lamps, especially those having a filling of neon gas, find considerable use for ornamental purposes or for sign lighting, and are particularly advantageous when used as small indicating or pilot lamps. These lamps employ a relatively low current and, when they are operated on commercial circuits, it is desirable to provide a resistance in series with each lamp for the purpose of preventing the passage of excessive currents therethrough. The stabilizing resistances frequently employed consist of separate units disposed in the line or of a separate resistanceelement of such character as to be contained either in the interior of the lamp or in the base thereof. My invention concerns itself with improving this part 0% the lamp.

One of the objects of my lnvention is to provide a lamp with a stabilizing resistance element which may constitute an integral part of a lamp.

Another object of my invention is the provision of an element which will serve a double purpose, namely, that of a stabilizing resistance and as an adhesive medium for securing one portion of a lamp to another.

A further object is the provision of a basing cement which will also serve as aresistance medium.

The above objects may be accomplished by providing a resistance material having an adhesive property necessary to a cement and capable of serving to unite the base of the lamp to the bulb. It is common, in the art of manufacturing electric lamps,'to secure thebase or screw cap to the bulb or -envelope in which the source of light is disposed by an interposed layer of cement. This cement, which is termed a basing cement, is usually of a suitable consistency to permit its flow into the base. In practice, the base and bulb are properly juxtaposed until the cement is pressed against the surface of the bulb and the inner surface of the base, after to electrical lamps lamps filled with a termed discharge,

which the cement, is hardened by baking,

thus bonding the base and the bulb.

In practicing my invention, I employ a suitable basing cement and combine therewith a conductive material in sufficient proportions to provide a given resistance, the

necessary adhesive property and the plasticity of the cement, previous to baking, being maintained.

By the provision of a resistance element incorporated in the cement, considerable advantage is derived, inasmuch as the necessity for external resistance devices is avoided and. no appreciable amount of s ace is required for my resistance element w en incorporated in a lamp.

The accompanying drawing illustrates an embodiment of my invention as applied to a lamp, part of the structure being shown in section.

The lamp (partly illustrated) may 15; of

any desired type having an envelope 2 containing a filling of a suitable gas and provided with leading-in wires 3 and &'which extend from, and are sealed in, a ressed portion 6 of the envelope. The lea 'ng-in wires conduct current to electrodes gpot shown) disposed within the envelope. he electrodes may be of any suitable form, depending upon the use to be made of the lamp. is provided and, in lamps of the ordinary type, this base is secured to the envelopeby' an adhesive medium or basing cement, and

one of the leading-in wires of the lamp is connected to the base, the other leading-in wire being connected to an external contact member 8 which is insulated from the shell or body of the base by a separator 9 made of glass or other insulating material.

A lamp constructed according to my invention may be provided with a cement constituting a combined resistance and adhesive substance 10 which may be termed a resistance element. An end 11 of the leading-in wire 4 projects from the envelope 2 a suflicient distance to permit a portion and, consequently a given area of the wire, to make contact with the resistance element 10. The leading-in wire 3 extends through the resistance element and the base 7 and is soldered, or otherwise secured, to the contact member 8.

As illustrated in the accompanying drawing, a portion of the leading-in wire 3 extends through the resistanee element or cement 10, which construction necessitates the provision of a layer of insulating material 12 to prevent short circuiting of the current. Such insulation may be of any desired material and-may be applied by the most con- A hollow threaded member or base 7 venient method. It has, however, been found desirable to employ any suitable insulating varnish or a viscous water solution of sodium silicate which may be applied tothe leading-in wire by means of a brush.

When this coating is dry, the layer 12, thus formed, furnishes an eflicient insulation. In order to more positively prevent any current from passing through the base ad'acent to the end of the leading-1n wire 3, a l ayer -14 of any suitable material as, for instance, glass-wool, asbestos-fiber or the like may be disposed between the end of the base 7 and the resistance element 10. Thus, the contact 8 is more perfectly insulated from the resistance element.

When the invention, as above set forth,

I is applied to a lamp of well known form, in

which a so-called fiare seal is employed, there will be, instead of'the press 6, as illustrated, a space between the resistance element 10 and the envelope which may be filled with glass-wool or insulating material. This will prevent the resistance element, when in a plastic state, from flowing in contact with leading in; wires.

In practice, the required portion ofthe leading-in wire 3 is given a coating of the insulating material 12. A predetermined amount of plastic cement, containing the proper proportion of conductive material, is then deposited in a base which is'slipped over the end of an envelope or bulb, the leading-in wire 3 being, at the same time, threaded through 'an aperture in the contact element 8 from which it slightly projects. The cement is then hardened by the usual baking process, after which the end of the leading-in wire 3 is soldered to the contact element 8. When the base containing the cement is applied to the bulb, it is obvious that the leading-in wire 4 which projects from the bulb will be disposed within the cement, consequently, when the cement hardens, a firm contact is secured between the wire and the cement or resistance element 10.

It will be appreciated that the resistance of the cement Or resistance element 10 will depend upon several factors, i. e., the diameter and length of the portion of the wire which makes contact with the element, the dimension of the base and the conductivity of the cement or resistance element. The latter factor is dependent upon the materials used to make a cement conductive and the relative amount of these conductive materials used.

The composition which I have found to tungsten powderv or powdered carbon; to this mixture may be added a suitable solvent, such as alcohol, in suificient proportion to produce a plastic composition of the desired viscosity.

In order to ensure a resistance of about 5000 ohms, using a standard candelabra base, having leading-in wires 4 of 25 mil wire, inch of one of the wires being in contact with the cement, a cement of the following composition may be used:

, Parts by weight.

Barium sulphate 3 Marble flour 8 Powdered graphite (pulverized electrode graphite) 3 The ingredients are intimately mixed and are made sufliciently plastic and adhesive by means of approximately 5 parts of a shellac solution. The barium sulphate, marble flour and powdered graphite are preferably fine enough to pass through a (SO-mesh screen. The shellac solution may be prepared by dissolving one pound of powdered bleached shellac in one quart of methyl alcohol or ethyl alcohol denatured with methyl alcohol.

Although I have obtained good results by the use of a shellac solution, it will be evident that, if desirable, the shellac may be mixed with the conductive substance and the filler, a suitable volatile solvent being added to this mixture to produce a plastic composition of appropriate viscosity. When a cement of relatively high temperature resistance is required, Bakelite may be substi tuted for shellac, but, if a cheaper productis desired, Albertol may be employed as the substitute.

The ingredients are intimately mixed until their consistency is such as to enable the composition to be readily poured or shaped into any desirable form, after which it may be baked until the solvent is volatilized and a relatively rigid tenacious product is ob tained.

It will thus be evident that I may prepare the composition of any workable consistency which will permit the composition to be poured and disposed in a given relation to one or more of the component parts of a device which may be secured together by the composition. Electrical conductors may be suitably disposed or embedded in the composition while in its plastic state and thus secured therein when the composition has become hardened by baking.

By the use of my invention, it is possible to manufacture glow lamps of very small size including a stabilizing resistance, and considerable advantage is thereby obtained. When it is desirable to employ a lamp having a small base, it is obvious that the desired results may be had by my comparatively simple construction and that a small lamp may be laced in a commercial line without expensive additions in the way of stabilizing resistance devices other than the self contained resistance element within the lamp.

Tie composition, when prepared in accordance with the above directions, is light in weight, has a high temperature resistance, does not crack in drying and possesses, in a high degree, all the desired properties of a cement and a resistance element.

Since my invention may be embodied in many other forms than that shown and described, I do not wish to be restricted to the exact form shown but intend to cover all modifications which lie within the scope of the appended claims.

What is claimed is:

1. An electric lamp having an envelope, a base, and a resistance element comprising an adhesive substance capable of securing the base to said envelope and serving as a part of a circuit for the passage of electrical energy to said lamp.

2. An electric gas lamp having an envelope and a base, said base being secured to said envelope by a cement capable of serving as a stabilizing resistance.

3. An electric gas lamp comprising an envelope, a base for said lamp, a substance for securing said base to said envelope, saidsubstance containing a conductive material whereby the said substance is adapted to serve as a stabilizing resistance.

4. An electric gas lamp comprising an envelope, leading-in wires projecting therefrom, a base for said lamp, a contact element insulated from said base and connected with one of said leading-in wires, a conductive adhesive substance disposed within said base to secure the base to said envelope, an end of the other of said leading-in wires being embedded in said substance, the other leading-in wire being insulated from said substance.

5. An electric gas lamp comprising an envelope having leading-in wires pro]ecting therefrom, a base secured to said envelope by an adhesive substance containing a conductive material to permit a flow of current from said base to a leading-in wire embedded in said material, a contact member associated with said base, the other leading-in wire being insulated from said material and connected to said contact member, said member being insulated from the body of said base.

6. An electric gas lamp comprising a bulb having a base secured thereto by a layer of adhesive resistance material, leading-in wires extending from said bulb, one of said wires being in contact with said material the other wire being insulated from said material.

7. An electric lamp comprising a base, a bulb having one end thereof positioned in said base, leading-in wires extending from said bulb, a layer of adhesive resistance substance interposed between said base and said bulb, an end of one of said leading-in wires connected to an external contact member and the end of the other leading-in wire embedded in said substance.

8. An electric lamp comprising a bulb having a base associated therewith, leadingin wires extending from said bulb, said base being provided with a contact member, one of said leading-in wires being connected to said member, the other leading-in wire projecting a given distance from said bulb, cement within said base and in contact with said last mentioned leading-in wire, said cement having conductive and adherent properties.

In testimony whereof, I have hereunto subscribed my name this 15 day of Feb, 1922.

CLETUS CLINTON VAN VOORHIS. 

